So far, several attempts have been made so as to provide an efficient process for preparing chalcopyrite-type compounds (such as CuInS2, CuInSe2, AgInS2, etc.) and other inorganic compounds such as compounds of families III-V or II-VI (for example InP, GaN, CdS, CdSe, etc.). Many of these proposed processes were related to the preparation of nanocrystalline compounds. However, several of the proposed solutions were related to costly and tedious processes. These processes often required costly reagents or comprised several steps. Some of these steps were also carried out under toxic conditions. Some colloidal processes have also been proposed but they often lead to compounds which are not highly crystalline.
Czekelius et al. in Advanced Materials, 1999, vol. 11(8), 643-646, describe a process for preparing nanocrystalline CuInS2. This two-steps process, however, requires the use of costly reagents. Also, this process uses phosphites which may form a resistive layer at the surface of the obtained CuInS2. Such a resistive layer may eventually cause a diminution of absorption of the visible light and a significant ohmic drop in a device incorporating such a material.
It would therefore be highly desirable to be provided with a process that would overcome the above-mentioned drawbacks.